Conventionally, a wire-bonding apparatus for connecting an electrode of a chip with an electrode of a substrate via a metallic wire has been known. Some examples of such a wire-bonding apparatus employ a wire tensioner for applying a wire with predetermined tension during wire bonding.
Patent Literature 1 describes a wire tensioner for applying a wire with back tension and provided between a capillary as a bonding tool and a wire spool for supplying a wire to the capillary. The wire tensioner is provided with a wire passage through which a wire passes from a wire spool side to a capillary side. The wire passage includes an inlet through which a compressed fluid enters, and an outlet that is disposed on the wire spool side of the inlet and through which the compressed fluid within the wire passage is discharged. The wire is pulled to the wire spool side by the compressed fluid that flows from the inlet to the outlet through the wire passage. In other words, a fluid resistance of the compressed fluid that flows through the wire passage applies the wire with back tension. Further, the wire passage also includes flow contraction portions having a smaller diameter than that of the inlet and the outlet. The flow contraction portions are respectively provided on the capillary side of the inlet and on the wire spool side of the outlet. As the flow contraction portions restrict passing of the compressed fluid, a flow of the compressed fluid from the inlet to the outlet is formed within the wire passage.
Patent Literature 2 describes a wire tensioner that applies a wire with predetermined tension in a direction toward a wire spool. To the wire tensioner, an air supply source for supplying compressed air, and a vacuum feeding source for producing a vacuum suction force by vacuuming are connected. The wire tensioner is configured such that the compressed air supplied to a wire passage by the air supply source is discharged through an outlet on the wire spool side. This configuration produces a fluid resistance of a fluid flowing from downstream to upstream of the wire passage, and a wire is applied with certain tension by this fluid resistance. The wire tensioner is also configured such that outer air that is suctioned through a capillary-side end of the wire passage flows through the wire passage to the vacuum feeding source by a vacuum suction force applied to the wire passage. This configuration produces a fluid resistance of a fluid flowing from downstream to upstream of the wire passage, and the wire is applied with certain tension by this fluid resistance.
Patent Literature 3 describes a wire cleaning guide through which a gas for plasma is supplied to clean a wire inserted therethrough. The wire cleaning guide includes a larger guide hole having a larger diameter and disposed on a spool side, a smaller guide hole having a diameter smaller than that of the larger guide hole and disposed on a capillary side, and a gas supply nozzle connected between these guide holes. The gas for plasma supplied from the gas supply nozzle flows toward the larger guide hole on the spool side, and this flow applies the wire with tension.